I've taken apart the machines from the "Requirements" thread, they're controller chips with internal roms like the 8741. Thanks for your offer, I'll contact you if he has any problems or ICs remain unread.

Hi Micko,the system uses the Z80 PIO, a D8741 for keyboard, a character EPROM, 256KB of RAM (1 page on the CPU card, 8 on a daughter card), a MK3886 for serial I/O, 256 bytes of shared RAM, 2 timers and interrupt control, a WD1791 floppy controller and a VTAC 5027/TMS 9927 Video controller.

I'm doing a quick translation from the system and user manuals that will contain a memory map.